The APOB Knockout HT29 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal population in the human HT29 colorectal adenocarcinoma line, designed to disrupt the APOB gene. This loss-of-function model enables investigation of apolipoprotein B (ApoB) in intestinal lipid transport, without selection of single-cell clones. The polyclonal composition provides a heterogeneous knockout background, suitable for studies of lipoprotein assembly, secretion, and metabolic regulation. Researchers can utilize these cells to dissect the molecular underpinnings of chylomicron formation and the consequences of ApoB deficiency in a human enterocyte-like system.
HT29 cells originate from a human colorectal adenocarcinoma and retain the ability to differentiate into polarized enterocyte-like monolayers with microvilli and brush-border enzymes. This characteristic makes them a relevant model for absorptive enterocyte biology, including nutrient uptake, lipid metabolism, and intestinal barrier functions. Their malignant origin adds value for exploring the intersection of cancer metabolism with lipid homeostasis. Cultured under standard or differentiation-inducing conditions, HT29 cells offer a tractable platform for studying the physiological roles of apolipoproteins in the intestinal epithelium.
The APOB gene produces apolipoprotein B, an obligatory structural component of chylomicrons and VLDL. ApoB lipidation, mediated by microsomal triglyceride transfer protein (MTP), is essential for the assembly and secretion of triglyceride-rich lipoproteins. APOB expression is regulated by SREBP1/2, LXR, PPAR??, and insulin, linking nutritional status to lipoprotein output. Downstream, secreted ApoB-containing particles bind LDL receptor (LDLR) and heparan sulfate proteoglycans (HSPGs) to mediate cholesterol delivery. Within this network, ApoB interacts with MTP, APOA1, APOC2, and APOE, coordinating particle maturation. Knockout of APOB abolishes chylomicron assembly, disrupting intestinal lipid transport and downstream cholesterol homeostasis.
In HT29 cells, APOB disruption eliminates chylomicron formation, creating a model of intestinal abetalipoproteinemia. This system permits dissection of dietary lipid handling, lipid droplet dynamics, and compensatory apolipoprotein pathways in an enterocyte-like background. The absence of ApoB also enables studies of lipotoxicity, metabolic stress, and the relationship between lipid metabolism and colorectal cancer cell growth. Because the knockout is polyclonal, population-level effects can be assessed without clonal bias, making it suitable for robust, reproducible assays in intestinal lipid biology.
Applications include intestinal lipid metabolism studies, lipoprotein assembly and secretion assays, and drug screening for dyslipidemia or cardiovascular disease. Representative experiments encompass western blotting, RT-qPCR, ApoB ELISA, BODIPY and Oil Red O staining, immunofluorescence, and MTP activity measurements. The model also facilitates functional genomics of apolipoproteins and investigation of cancer lipid metabolism. For further details or customization, please reach out to Ascent Research.
